More and more people care about the display medium of an electronic device, such as mobile phones, notebook computers, portable games and PDAs. In order to increase the area of the display medium, some electronic devices are constructed in foldable type or slidable type. Though the sliding type electronic device is much appreciated by the consumers but the structure is somewhat complicated.
Presently, most of the mobile phones are designed in the sliding type. However, one part is moved manually to space apart from the other. Only a few mobile phones are provided with automatic sliding mechanism at the distal portion thereof so that one part may eject out from the other in a sudden impact, thereby retaining the parts at the use position. It is noted that the sudden impact resulted from ejection of one part relative to the other may cause discomfort to the user.
It is for the manufacturers to explore, which type of coupling structure is handy for the electronic device. In the past, a coil spring is used to interconnect two metal parts so as to provide handy feeling to the user. However, the restoration force of the coil spring depends on the thickness of the coil or diameter of the coil. Due to limited space in the electronic device, it is difficult to adjust the diameter of the coil, thereby restricting the utility of such coil spring in the electronic device and cannot fulfill the designed requirement of the user.
In another prior art technology, a resilient member is used for interconnecting two metal parts of the electronic device. The problem resides in that the resilient member has a plurality of coils overlapping one another and it is relatively hard to control the restoration force of the resilient member. Though, the coils can be stored in the overlapped manner but still occupy a relatively large thickness and is therefore against the trend to produce the device in compact size.
In order to enhance the deformation range of the resilient member or springs, the latter may have symmetric wave-like sections for interconnecting two metal parts of the electronic device. Slidable movement between the metal parts is quite large and may result in pressing of the wave-like sections into curved formations when moving toward each other and the restoration force provided thereby is poor and non-suitable in practical use.